The urgency of resuming disrupted dog rabies vaccination campaigns: a modeling and cost-effectiveness analysis.

Dog vaccination is a cost-effective approach to preventing human rabies deaths. In Haiti, the last nation-wide dog vaccination campaign occurred in 2018. We estimated the number of human lives that could be saved by resuming dog vaccination in 2021 compared to 2022 and compared the cost-effectiveness of these two scenarios. We modified a previously published rabies transmission and economic model to estimate trends in dog and human rabies cases in Haiti from 2005 to 2025, with varying assumptions about when dog vaccinations resume. We compared model outputs to surveillance data on human rabies deaths from 2005 to 2020 and animal rabies cases from 2018 to 2020. Model predictions and surveillance data both suggest a 5- to 8-fold increase in animal rabies cases occurred in Haiti's capital city between Fall 2019 and Fall 2020. Restarting dog vaccination in Haiti in 2021 compared to 2022 could save 285 human lives and prevent 6541 human rabies exposures over a five-year period. It may also decrease program costs due to reduced need for human post-exposure prophylaxis. These results show that interruptions in dog vaccination campaigns before elimination is achieved can lead to significant human rabies epidemics if not promptly resumed.

How geographic access to care shapes disease burden: The current impact of post-exposure prophylaxis and potential for expanded access to prevent human rabies deaths in Madagascar.

BACKGROUND: Post-exposure prophylaxis (PEP) is highly effective at preventing human rabies deaths, however access to PEP is limited in many rabies endemic countries. The 2018 decision by Gavi to add human rabies vaccine to its investment portfolio should expand PEP availability and reduce rabies deaths. We explore how geographic access to PEP impacts the rabies burden in Madagascar and the potential benefits of improved provisioning. METHODOLOGY & PRINCIPAL FINDINGS: We use spatially resolved data on numbers of bite patients seeking PEP across Madagascar and estimates of travel times to the closest clinic providing PEP (N = 31) in a Bayesian regression framework to estimate how geographic access predicts reported bite incidence. We find that travel times strongly predict reported bite incidence across the country. Using resulting estimates in an adapted decision tree, we extrapolate rabies deaths and reporting and find that geographic access to PEP shapes burden sub-nationally. We estimate 960 human rabies deaths annually (95% Prediction Intervals (PI): 790-1120), with PEP averting an additional 800 deaths (95% PI: 640-970) each year. Under these assumptions, we find that expanding PEP to one clinic per district (83 additional clinics) could reduce deaths by 19%, but even with all major primary clinics provisioning PEP (1733 additional clinics), we still expect substantial rabies mortality. Our quantitative estimates are most sensitive to assumptions of underlying rabies exposure incidence, but qualitative patterns of the impacts of travel times and expanded PEP access are robust. CONCLUSIONS & SIGNIFICANCE: PEP is effective at preventing rabies deaths, and in the absence of strong surveillance, targeting underserved populations may be the most equitable way to provision PEP. Given the potential for countries to use Gavi funding to expand access to PEP in the coming years, this framework could be used as a first step to guide expansion and improve targeting of interventions in similar endemic settings where PEP access is geographically restricted and baseline data on rabies risk is lacking. While better PEP access should save many lives, improved outreach, surveillance, and dog vaccination will be necessary, and if rolled out with Gavi investment, could catalyze progress towards achieving zero rabies deaths.

An assessment of risk factors for contracting rabies among dog bite cases recorded in Ward 30, Murewa district, Zimbabwe.

BACKGROUND: Zoonoses are a major threat to human health. Worldwide, rabies is responsible for approximately 59 000 deaths annually. In Zimbabwe, rabies is one of the top 5 priority diseases and it is notifiable. It is estimated that rabies causes 410 human deaths per year in the country. Murewa district recorded 938 dog bite cases and 4suspected rabies deaths between January 2017 and July 2018, overshooting the threshold of zero rabies cases. Of the 938dog bite cases reported in the district, 263 were reported in Ward 30 and these included all the 4suspected rabies deaths reported in the district. This necessitated a study to assess risk factors for contracting rabies in Ward 30, Murewa. METHODOLOGY/ PRINCIPAL FINDINGS: A descriptive cross sectional survey was used for a retrospective analysis of a group of dog bite cases reported at Murewa Hospital, in Ward 30. Purposive sampling was used to select dog bite cases and snowball sampling was used to locate unvaccinated dogs and areas with jackal presence. The dog bite cases and relatives of rabies cases were interviewed using a piloted interviewer-administered questionnaire. Geographical Positioning System (GPS) coordinates of dog bite cases, vaccinated and unvaccinated dogs and jackal presence were collected using handheld GPS device. QGIS software was used to spatially analyse and map them. Dog owners were 10 times more likely to contract rabies compared to non-dog owners (RR = 10, 95% CI 1.06-93.7). Owners of unvaccinated dogs were 5 times more likely to contract rabies compared to owners of vaccinated dogs (RR = 5.01, 95% CI 0.53-47.31). Residents of the high density cluster (area with low cost houses and stand size of 300 square meters and below) were 64 times more likely to contract rabies compared to non-high density cluster residents (RR = 64.87, 95% CI 3.6039-1167.82). Participants who were not knowledgeable were 0.07 times more likely to contract rabies, compared to those who had knowledge about rabies. (RR = 0.07, 95% CI 0.004-1.25). Our study shows that the risk factors for contacting rabies included; low knowledge levels regarding rabies, dog ownership residing in the high density cluster, owning unvaccinated dogs and spatial overlap of jackal presence with unvaccinated dogs.

RABIES IMMUNOGLOBULIN: Brief history and recent experiences in Côte d'Ivoire.

BACKGROUND: Rabies is a fatal viral zoonosis mainly transmitted via dog bites. The estimated 59'000 annual deaths caused by the disease are preventable through correct and timely administration of post-exposure prophylaxis (PEP). PEP should be initiated as soon as possible after an exposure to a rabies suspected animal and consists of a course of active vaccinations and administration of rabies immunoglobulin (RIG) in case of severe exposure. However, RIG is not accessible in most rabies endemic countries and its impact on survival in combination with modern vaccines and its cost-effectiveness is unclear. We examined the effect of equine RIG (eRIG) in a field-trial in Côte d'Ivoire, a developing country with low but chronic rabies burden and persistent lack of RIG, similar to a majority of rabies endemic countries attempting elimination of the disease. METHODS: Data from 3367 patients attending anti-rabies centers (Centres Anti-Rabiques, CARs) of the National Institute for Public Hygiene (Institut National d'Hygiène Publique, INHP) in the departments of Bouaké and San Pédro in Côte d'Ivoire was prospectively collected between April 2016 and March 2018. We identified 1594 patients at risk of rabies infection as eligible for RIG administration. Depending on local availability of eRIG and vaccination protocol applied, PEP consisted of active immunization only (non-eRIG group, n = 1145) or active and passive immunization (eRIG group, n = 449). Patients were followed-up by phone interviews at least 15 months after their exposure to assess for rabies suspected deaths. RESULTS: Follow-up data was available for 641 patients in the non-eRIG group (56%) and 242 in the eRIG group (54%). Three suspected or possible rabies deaths occurred in each of the two groups, corresponding to a possible rabies mortality of 1.2% (95% CI 0.3-3.6%) in the eRIG group and 0.5% (95% CI 0.1-1.4%) in the non-eRIG group. The difference in proportions was small and not statistically significant (0.7%, p = 0.21). Deaths in both groups were associated with treatment delay after exposure and non-compliance to PEP protocol. No death occurred after correct and timely active immunization independent of eRIG administration. CONCLUSION: The provision of eRIG did not lead to a measurable reduction of rabies burden in our study population. This underlines that improved access to active vaccines will be effective in reducing rabies deaths even if access to eRIG remains difficult in developing countries. A possible benefit of eRIG administration for severely exposed patients cannot be excluded based on these results.

Health economic assessment of a rabies pre-exposure prophylaxis program compared with post-exposure prophylaxis alone in high-risk age groups in the Philippines.

OBJECTIVES: Once symptoms appear, rabies is almost always fatal and accounts for 200-300 deaths annually in the Philippines. Available rabies vaccines can be administered either in pre- exposure prophylaxis (PrEP) or post-exposure prophylaxis (PEP). After exposure, PrEP-immunized individuals require fewer doses of PEP and no rabies immunoglobulin. METHODS: A static decision-tree model was developed to assess cost-effectiveness of a PrEP+PEP program vs PEP alone. Philippines-specific data for people seeking medical advice at the Research Institute for Tropical Medicine between July 2015 and June 2016 were used in the model, together with data from published literature. RESULTS: Over a 20-year period, in a cohort of 1 million 5-year-old children in the Philippines, PrEP+PEP was expected to prevent 297 deaths compared with PEP alone. From both payer and societal perspectives, the resulting incremental cost-effectiveness ratios were 36 035 (US$759; 2016 US$ conversion) and 18 663 (US$393) Philippine Pesos (PHP) - quality-adjusted life-years gained - respectively, which are both below the willingness-to-pay threshold of PHP140 255 (US$2 953). CONCLUSION: These data suggest that a universal PrEP program targeting 5-year-olds would be cost-effective in the Philippines.

Wound-only injection of rabies immunoglobulin (RIG) saves lives and costs less than a dollar per patient by "pooling strategy".

Since 2008, we in Himachal Pradesh have used a "pooling strategy" to help patients save money by pooling vials of antirabies vaccine at a centralized hospital and sharing them using the intradermal technique. In 2014, there was an acute shortage of rabies immunoglobulins (RIG) and two patients died after four injections of rabies vaccine were administered without RIG, which was not commercially available. After an extensive literature review and technical and ethical committee clearances, in June 2014 we started to infiltrate equine RIG (eRIG) into wound/s only without the recommended systemic intramuscular (IM) injection. WHO recommended this technique in 2018. During the four-year period June 2014 to June 2018, 7506 of 10,830 patients exposed to suspected rabid animals were injected with eRIG in and around the wounds in a single clinic at DDU Hospital Shimla without any adverse outcomes. The average volume of eRIG used per patient was 0.75 mL and cost US$ 0.75. Of the 80% of patients who were followed up, all were healthy at the end of a year, including 26 patients bitten by laboratory-confirmed rabid dogs. The reaction rate after PEP administration also declined significantly. Since February 2018, Himachal has started following the new WHO recommendations on PEP regimens of three intradermal antirabies vaccines instead of four, thereby saving hundreds of vaccine vials that became useful during shortages of rabies vaccine in India. To date, more than 700 vaccine vials have been saved in a single clinic at DDU hospital during the past 6 months alone. Not giving PEP to patients who have consumed raw milk from a suspected rabid cow has also saved 62 vials. Currently, 90 "pooling centers" have been established for sharing of vaccine and eRIG vials in Himachal State, generating huge savings that have enabled the government to provide PEP free of charge to all. The new WHO guidelines are a positive step towards a rabies-free world by 2030.

Rabies post-exposure prophylaxis initiation and adherence among patients in Vietnam, 2014-2016.

BACKGROUND: Adhering to post-exposure prophylaxis (PEP): wound treatment, vaccine, and rabies immunoglobulin (RIG) is a crucial step in preventing rabies mortality. When PEP is widely available, a lack of adherence to the recommended treatment guidelines can also lead to death. Our objective was to understand characteristics associated with adherence to the vaccine regimen and RIG in Vietnam. METHODS: We obtained individual-level data on PEP adherence from registries at 10 sites located in five provinces. From these registries, we extracted epidemiologic characteristics of patients including the timing of PEP initiation and completion. We used descriptive analyses and logistic regression to examine patient characteristics associated with initiation and completion of RIG and vaccine. Based on reported rabies mortality, the government defined provincial rabies burden as medium-burden (<5 and >2 deaths) and high-burden (≥5 deaths). RESULTS: During 2014-2016, 15,646 patients received PEP in our study. Among 14,296 vaccinated patients, only 41.4% (5847) completed their five-dose intramuscular (IM) injections and 81.6% (133) of patients completed their eight-dose intradermal (ID) injections. Approximately 26% of patients received RIG. Patient characteristics associated with vaccine completion were females (44%), <15 years of age (44%), category 1 exposure (68%, bite location on leg (46%), bite from bat (56%), bite from a healthy animal (45%), high-burden province (86%), and district preventive center (49%). Disparities were revealed among provinces, with high-burden provinces having highest (86%) and lowest (7%) vaccine completion rates. CONCLUSIONS AND RELEVANCE: Vietnam has made tremendous progress towards reducing the burden of rabies. However, despite the wide availability of PEP, we found relatively low rates of vaccine completion. Our findings suggest provider training and patient education is needed to ensure appropriate treatment is completed. Moreover, our data suggest changes to information reported through the national surveillance system for monitoring good clinical practice for rabies prevention and control.

The potential effect of improved provision of rabies post-exposure prophylaxis in Gavi-eligible countries: a modelling study.

BACKGROUND: Tens of thousands of people die from dog-mediated rabies annually. Deaths can be prevented through post-exposure prophylaxis for people who have been bitten, and the disease eliminated through dog vaccination. Current post-exposure prophylaxis use saves many lives, but availability remains poor in many rabies-endemic countries due to high costs, poor access, and supply. METHODS: We developed epidemiological and economic models to investigate the effect of an investment in post-exposure prophylaxis by Gavi, the Vaccine Alliance. We modelled post-exposure prophylaxis use according to the status quo, with improved access using WHO-recommended intradermal vaccination, with and without rabies immunoglobulin, and with and without dog vaccination. We took the health provider perspective, including only direct costs. FINDINGS: We predict more than 1 million deaths will occur in the 67 rabies-endemic countries considered from 2020 to 2035, under the status quo. Current post-exposure prophylaxis use prevents approximately 56 000 deaths annually. Expanded access to, and free provision of, post-exposure prophylaxis would prevent an additional 489 000 deaths between 2020 and 2035. Under this switch to efficient intradermal post-exposure prophylaxis regimens, total projected vaccine needs remain similar (about 73 million vials) yet 17·4 million more people are vaccinated, making this an extremely cost-effective method, with costs of US$635 per death averted and $33 per disability-adjusted life-years averted. Scaling up dog vaccination programmes could eliminate dog-mediated rabies over this time period; improved post-exposure prophylaxis access remains cost-effective under this scenario, especially in combination with patient risk assessments to reduce unnecessary post-exposure prophylaxis use. INTERPRETATION: Investing in post-exposure vaccines would be an extremely cost-effective intervention that could substantially reduce disease burden and catalyse dog vaccination efforts to eliminate dog-mediated rabies. FUNDING: World Health Organization.

Healthcare utilization, provisioning of post-exposure prophylaxis, and estimation of human rabies burden in Madagascar.

In Madagascar, dog-mediated rabies has been endemic for over a century, however there is little data on its incidence or impact. We collected data over a 16-month period on provisioning of post-exposure prophylaxis (PEP) at a focal clinic in the Moramanga District and determined the rabies status of biting animals using clinical and laboratory diagnosis. We find that animal rabies cases are widespread, and clinic-based triage and investigation are effective ways to increase detection of rabies exposures and to rule out non-cases. A high proportion of rabies-exposed persons from Moramanga sought (84%) and completed PEP (90% of those that initiated PEP), likely reflecting the access and free provisioning of PEP in the district. Current clinic vial sharing practices demonstrate the potential for intradermal administration of PEP in endemic African settings, reducing vaccine use by 50% in comparison to intramuscular administration. A high proportion of PEP demand was attributed to rabies cases, with approximately 20% of PEP administered to probable rabies exposures and an additional 20% to low-to-no risk contacts with confirmed/probable animal or human cases. Using a simplified decision tree and our data on rabies exposure status and health-seeking behavior, we estimated an annual incidence of 42-110 rabies exposures and 1-3 deaths per 100,000 persons annually. Extrapolating to Madagascar, we estimate an annual burden of 282-745 human rabies deaths with current PEP provisioning averting 1499-3958 deaths each year. Data from other clinics and districts are needed to improve these estimates, particularly given that PEP availability is currently limited to only 31 clinics in the country. A combined strategy of mass dog vaccination, enhanced surveillance, and expanded access to PEP along with more judicious guidelines for administration could effectively reduce and eventually eliminate the burden of rabies in Madagascar.

The evaluation of operating Animal Bite Treatment Centers in the Philippines from a health provider perspective.

BACKGROUND: The Philippine government has an extensive network of 513 Animal Bite Treatment Centers (ABTCs) to supply rabies post exposure prophylaxis (PEP), reaching over 1 million bite victims in 2016. The network was evaluated using a review of existing national and provincial data, key informant interviews and surveys in sample ABTCs to determine the cost-effectiveness of this network in preventing human rabies deaths. METHODOLOGY AND PRINCIPAL FINDINGS: One urban and one rural ABTC in each of three selected provinces were studied in more detail. PEP delivery generally followed national guidance based on best practices, but there was evidence of operational challenges in supplying all ABTCs with adequate biologics and recently trained staff. Funding was contributed by different levels of government and in some clinics, patients paid for a significant fraction of the total cost. From a health provider perspective including both fixed and variable costs, the average PEP course delivered cost USD 32.91 /patient across urban ABTCs (with higher patient throughput) and USD 57.21 /patient across rural ABTCs. These costs suggests that PEP provision in the Philippines cost USD 37.6 million in 2016, with a cost per life saved of USD 8,290. An analysis of the 2,239 suspected rabies deaths from 2008 to 2016 showed no significant decline, and from 2014-16 an average of 8,534 years of life were lost annually. The incidence of rabies deaths from 2014-16 was not clearly related to the provision of ABTCs (per 100,000 population) or human population density, but deaths were more common in higher income provinces. CONCLUSIONS/SIGNIFICANCE: In the context of comprehensive rabies control (including dog vaccination and public awareness) ways to reduce this high expenditure on PEP should be explored, to most cost-effectively reach the elimination of human rabies deaths. This paper is accompanied by another containing data on the operation of ABTCs network from a patient perspective.

Cost-effectiveness of dog rabies vaccination programs in East Africa.

BACKGROUND: Dog rabies annually causes 24,000-70,000 deaths globally. We built a spreadsheet tool, RabiesEcon, to aid public health officials to estimate the cost-effectiveness of dog rabies vaccination programs in East Africa. METHODS: RabiesEcon uses a mathematical model of dog-dog and dog-human rabies transmission to estimate dog rabies cases averted, the cost per human rabies death averted and cost per year of life gained (YLG) due to dog vaccination programs (US 2015 dollars). We used an East African human population of 1 million (approximately 2/3 living in urban setting, 1/3 rural). We considered, using data from the literature, three vaccination options; no vaccination, annual vaccination of 50% of dogs and 20% of dogs vaccinated semi-annually. We assessed 2 transmission scenarios: low (1.2 dogs infected per infectious dog) and high (1.7 dogs infected). We also examined the impact of annually vaccinating 70% of all dogs (World Health Organization recommendation for dog rabies elimination). RESULTS: Without dog vaccination, over 10 years there would a total of be approximately 44,000-65,000 rabid dogs and 2,100-2,900 human deaths. Annually vaccinating 50% of dogs results in 10-year reductions of 97% and 75% in rabid dogs (low and high transmissions scenarios, respectively), approximately 2,000-1,600 human deaths averted, and an undiscounted cost-effectiveness of $451-$385 per life saved. Semi-annual vaccination of 20% of dogs results in in 10-year reductions of 94% and 78% in rabid dogs, and approximately 2,000-1,900 human deaths averted, and cost $404-$305 per life saved. In the low transmission scenario, vaccinating either 50% or 70% of dogs eliminated dog rabies. Results were most sensitive to dog birth rate and the initial rate of dog-to-dog transmission (Ro). CONCLUSIONS: Dog rabies vaccination programs can control, and potentially eliminate, dog rabies. The frequency and coverage of vaccination programs, along with the level of dog rabies transmission, can affect the cost-effectiveness of such programs. RabiesEcon can aid both the planning and assessment of dog rabies vaccination programs.

Cost-effectiveness of rabies post-exposure prophylaxis in the context of very low rabies risk: A decision-tree model based on the experience of France.

INTRODUCTION: Benefit-risk of different anti-rabies post-exposure prophylaxis (PEP) strategies after scratches or bites from dogs with unknown rabies status is unknown in very low rabies risk settings. DESIGN AND SETTING: A cost-effectiveness analysis in metropolitan France using a decision-tree model and input data from 2001 to 2011. POPULATION: A cohort of 2807 patients, based on the mean annual number of patients exposed to category CII (minor scratches) or CIII (transdermal bite) dog attacks in metropolitan France between 2001 and 2011. INTERVENTIONS: Five PEP strategies: (A) no PEP for CII and CIII; (B) vaccine only for CIII; (C) vaccine for CII and CIII; (D) vaccine+ rabies immunoglobulin (RIG) only for CIII; and (E) vaccine for CII and vaccine+ RIG for CIII. MAIN OUTCOMES MEASURES: The number of deaths related to rabies and to traffic accidents on the way to anti-rabies centers (ARC), effectiveness in terms of years of life gained by reducing rabies cases and avoiding traffic accidents, costs, and incremental cost-effectiveness ratios (ICER) associated with each strategy. RESULTS: Strategy E led to the fewest rabies cases (3.6 × 10(-8)) and the highest costs (€ 1,606,000) but also to 1.7 × 10(-3) lethal traffic accidents. Strategy A was associated with the most rabies cases (4.8 × 10(-6)), but the risk of traffic accidents and costs were null; therefore, strategy A was the most effective and the least costly. The sensitivity analysis showed that, when the probability that a given dog is rabid a given day (PA) was > 1.4 × 10(-6), strategy D was more effective than strategy A; strategy B became cost-effective (i.e. ICER vs strategy A < 3 × French Gross Domestic Product per capita) when PA was > 1 .4 × 10(-4). CONCLUSIONS: In the metropolitan France's very low rabies prevalence context, PEP with rabies vaccine, administered alone or with RIG, is associated with significant and unnecessary costs and unfavourable benefit-risk ratios regardless to exposure category.

Human rabies deaths in Africa: breaking the cycle of indifference.

The current outbreak of Ebola virus disease has mobilized the international community against this deadly disease. However, rabies, another deadly disease, is greatly affecting the African continent, with an estimated 25 000 deaths every year. And yet, the disease can be prevented by a vaccine, if necessary with immunoglobulin, even when administered after exposure to the rabies virus. Rabies victims die because of neglect and ignorance, because they are not aware of these life-saving biologicals, or because they cannot access them or do not have the money to pay for them. Breaking the cycle of indifference of rabies deaths in humans in Africa should be a priority of governments, international organizations and all stakeholders involved.

Review of rabies epidemiology and control in South, South East and East Asia: past, present and prospects for elimination.

Rabies is a serious public health problem in Asia. It causes substantial animal welfare, economic and human health impacts, with approximately 39,000 human deaths each year. Domestic dogs are the main reservoir and source of rabies in Asia. Common constraints for the control of rabies in the countries of Asia include inadequate resources; lack of political commitment to control programs; lack of consensus on strategy; weak intersectoral coordination and inadequate management structure; insensitive surveillance systems; limited accessibility to modern rabies vaccine and supply problems; lack of public awareness and public cooperation; and the existence of myths and religious issues. In this review, we summarize the epidemiology of rabies in both human and animals in each South and South East Asian country, the past and current approaches to control and the prospect for rabies elimination. We conclude that defining the cost of rabies to society and communicating this to decisionmakers might be the key to achieving such an advance.

Preventative childhood vaccination to rabies.

INTRODUCTION: Rabies is prevented by post-exposure vaccination with several doses of vaccine given over 4 - 14 weeks. In case of severe exposure, the first dose of vaccine is combined with passive transfer of a rabies virus-specific immunoglobulin preparation. Preventative vaccination for rabies, also referred as pre-exposure vaccination, is reserved for humans at high risk. Although available vaccines are efficacious in preventing disease, rabies still claims the lives of an estimated 55,000 humans residing in Africa and Asia each year. Half of the death occurs in children under the age of 15. AREAS COVERED: This paper discusses whether preventative vaccination of all children in Africa and Asia, which was deemed non-cost-effective compared to post-exposure vaccination using currently licensed vaccines in Thailand, could be cost-effective using more immunogenic novel vaccines. EXPERT OPINION: At least in theory, novel one-dose rabies vaccines may be cost-effective for preventative childhood immunization, which in turn should reduce the incidence of this disease. Further clinical testing of such vaccines with the goal to develop a low-cost vaccine that can be incorporated into childhood immunization programs for areas with a high incidence of rabies-related death should be strongly encouraged.

[Transmission dynamics and cost-effectiveness of rabies control in dogs and humans in an African city]. / Dynamique de transmission et coût de la lutte contre la rage chez les chiens et les hommes dans une ville Africaine.

Control of human rabies in developing countries depends on prevention in dogs. The purpose of this study was to evaluate the cost-saving potential for the public health sector of intervention to control rabies in animal-host reservoirs. An existing deterministic model was adapted to allow study of dog-to-human rabies transmission. Model parameters were fitted to data from routine weekly reports on the number of rabid dogs and human rabies exposures in N'Djamena, Chad. At the onset of study, the estimated effective reproductive ratio (Re) was 1.01 indicating stable low-level endemic rabies transmission. Simulations were performed to determine what effects mass vaccination and culling of dogs would have on the incidence of human rabies. Findings showed that a mass campaign allowing single parenteral vaccination of at least 70% of the canine population would be sufficient to interrupt transmission of rabies to humans for at least 6 years. The cost-effectiveness of mass dog vaccination was compared to that of "postexposure prophylaxis" (PEP) which would not reduce future human exposure. Results showed that a sustained 5-year PEP program together with a dog-vaccination campaign would be as cost-effective as PEP alone. Beyond a time-frame of 7 years, combining parenteral dog vaccination campaigns with human PEP appeared to be more cost-effective than human PEP alone.

Reemergence of rabies in Chhukha district, Bhutan, 2008.

From January through July 2008, rabies reemerged in the Chhukha district of southwestern Bhutan. To clarify the distribution and direction of spread of this outbreak, we mapped reported cases and conducted directional tests (mean center and standard deviational ellipse). The outbreak resulted in the death of 97 animals (42 cattle, 52 dogs, and 3 horses). Antirabies vaccine was given free of charge to ≈674 persons suspected to have been exposed. The outbreak spread south to north and appeared to follow road networks, towns, and areas of high human density associated with a large, free-roaming, dog population. The outbreak was controlled by culling free-roaming dogs. To prevent spread into the interior of Bhutan, a well-coordinated national rabies control program should be implemented in disease-endemic areas.